Programmable hearing aids, such as the hearing aid disclosed in U.S. Pat. No. 4,425,481 (Mansgold et al., 1984) can store a number of distinct programs, or sets of parameter values, each designed for use in different audio environments. For instance, a hearing aid that stores eight distinct programs can have programs for a variety of situations, such as conversing with one person in a quiet room, conversing with several persons in an otherwise fairly quiet environment, conversing with one or more persons in settings with increasing levels of background noise, walking or commuting environments with large noise variations, listening to music in a quiet room, and listening to music in a noisy environment. U.S. Pat. No. 4,425,481 is hereby incorporated by reference.
The various programs in a programmable hearing aid must be customized to compensate for an individual's particular hearing deficiencies. However, some aspects of hearing aid programming are inherently subjective on the part of the user -- and therefore hearing aids often must be reprogrammed several times before an optimal set of programs is found. In addition, a person's hearing characteristics may change over time, requiring adjustment of the programs stored in a programmable hearing aid. As a result, programmable hearing aids should be easily reprogrammed.
A copending application, Ser. No. 175,233, entitled AUDITORY PROSTHESIS WITH DATALOGGING CAPABILITY, filed on Mar. 30, 1988, discloses a datalogging system for generating a record of the frequency of usage of each of the programs in a programmable hearing aid. Application Ser. No. 175,233 is hereby incorporated by reference.
Another copending application, Ser. No. 07/192,242 entitled HEARING AID PROGRAMMING INTERFACE, filed on the same date as this application, discloses a miniature interface in a hearing aid, and a corresponding connector, for connecting a hearing aid to a computer reprogramming the device. Application Ser. No. 07/792,242 is also hereby incorporated by reference.
When a programmable hearing aid is programmed with new data, or when a multiple-memory hearing aid is loaded with a new set of data, several considerations must be taken into account. In particular, the programming process should be as fast as possible while being verifiably error free.
In addition, it is desirable to be able to program the hearing aid without removing the hearing aid from the user's ear. However, it would be unacceptable for the hearing aid to generate unpredictably loud and possibly injurious sounds during the programming procedure. In particular, during the programming or program loading process the signal processor in the hearing aid may be temporarily placed into an indeterminate state. This indeterminate state is caused by the fact that it takes a finite amount of time to load a new set of program data into the signal processor, and that the program characteristics of the signal processor during the loading of the program data will be unpredictable. Another problem with the loading of new program data while the hearing aid is still mounted in the user's ear is that the programming process may generate digital noise that affects the operation of the hearing aid.
To prevent operation of the hearing aid when it is in an indeterminate state, and to prevent any possibility of unpleasant and possibly injurious sounds being generated during program selection and reprogramming, the present invention automatically mutes the hearing aids amplification functions during the loading of new program data. Muting is automatically terminated only when the newly loaded program data has been verified as error free. The muting function is also temporarily activated whenever the user switches programs so that the hearing aid's amplification functions are disabled until the new program has been fully loaded into the hearing aid's amplification control circuitry.